Photovoltaic Irrigation Systems Research Articles

Feasibility analysis of photovoltaic systems for kiwifruit irrigation: A case study in Shaanxi province, China

AbstractAlthough photovoltaic (PV) irrigation systems are widely used in China, feasibility assessment of these systems is important because of differences in the distribution characteristics of solar resources and crops. In this study, kiwifruit planting in Shaanxi province was considered, and a calculation model for PV irrigation system evaluation was developed. Based on the geographical distribution of kiwifruit planting, as well as the spatial and temporal distributions of solar energy in Shaanxi province, the application potential of PV irrigation for kiwifruit was investigated comprehensively from the perspectives of technology, economy and irrigation feasibility. The results showed that the proportion of the PV module scale to the irrigation scale in all the kiwifruit planting areas in Shaanxi province was far less than 1.5%, and there were no technical obstacles. In Baoji, Weinan, Hanzhong and Ankang, the annual cost of the PV irrigation system was greater than that of the diesel pump irrigation system. Regarding irrigation feasibility, farmlands with a slope of 0%–8.75% were considered highly suitable for installing a PV irrigation system. The results revealed 32,269 ha of farmland appropriate for PV irrigation among the 66,371 ha of kiwifruit in Shaanxi province.

A Sensorless MPPT Approach For PV Pumb System Used BLDC Motor

PV irrigation systems have begun to be used intensively today, as energy needs increase. In Partially Shaded Conditions (PSC), the efficiency of the PV system decreases significantly, and traditional Maximum Power Point Tracking (MPPT) algorithms become insufficient. On the other hand, traditional MPPT algorithms require sensors to measure the current and voltage of the PV system. In this study, a sensorless hybrid MPPT algorithm is proposed to reduce system costs and enable operation without the need for PV system data. A simulation study was conducted in the MATLAB/Simulink environment to examine the PV system. The proposed algorithm has been tested under four different PSC scenarios. PV system power, motor speed, and currents were examined under each condition. The high maximum power tracking performance of the proposed algorithm is demonstrated through simulation results. In the steady state, the lowest MPPT efficiency was 95.66%, whereas the highest MPPT efficiency was 99.9%. The MPPT algorithm completed in less than 2 seconds, with the first stage taking 1.3 seconds to reach most of the maximum PV system power. The second stage of the MPPT algorithm was used to achieve maximum power in a narrower area.

Effect of Irrigation Interval on Growth and Forage Yield of Maize (Zea Mays) Variety Using Solar Photovoltaic Irrigation system in Sokoto, Nigeria

Experiment was conducted at the Usmanu Danfodyio University Dryl and Teaching and Research Farm (130 01 N and 50 13 E), during 2022 dry seasons. The objective of the research was to study the effect of irrigation interval on the growth and forage yield of cowpeas varieties using Solar PV Irrigation system. (SAMMAZ 15, SAMMAZ 33 and Ex Dundaye) respectively, with irrigation intervals of 3, 4 and 5 days respectively were used for the experiment. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Results from the research shows that variety had significant effect on stand establishment count, leaf length, leaf with, number of leave per plant, days to 50% tas selling and forage yield. Also, irrigation interval had significant effect on plant height, number of leaves, leaves length, days to 50% tasseling and forage yield. Interaction effects between variety and irrigation interval was also found to be significant. From this research, it was found that production of SAMMAZ 15 with 3 days irrigation interval is encouraged in Sokoto ecological condition using Solar PV irrigation system.

An Automatic PI Tuning Method for Photovoltaic Irrigation Systems Based on Voltage Perturbation Using Feedforward Input

This paper proposes a new automatic tuning method for the proportional-integral (PI) controllers of photovoltaic irrigation systems (PVIS) without the need for any other power source or batteries. It enables the optimisation of the values of the PI parameters (Kp and Ki) automatically, eliminating the requirement for skilled personnel during the installation phase of PVIS. This method is based on the system’s voltage response when a disturbance signal is introduced through the feedforward input of the PI controller. To automatically assess the response properties, two indicators are proposed: the total harmonic distortion (THD), used to evaluate the sine response, and the total square distortion (TSD), used to evaluate the square response. The results indicate that the tuning changes for different irradiance and temperature conditions due to the non-linearity of the system, obtaining the most conservative values at maximum irradiance and temperature. The robustness of the results of the new automatic tuning method to abrupt photovoltaic (PV) power fluctuations due to clouds passing over the PV generator has been experimentally tested and the results show that the obtained tuning values make the PVIS stable, even when PV power drops of 66% occur abruptly.

Solar irrigation in sub-Saharan Africa: economic feasibility and development potential

Irrespective of water resource abundance, agriculture in sub-Saharan Africa (SSA) is predominantly rainfed. Along with fertilization, irrigation could support smallholder farmers with stabilizing crop yields, increasing incomes, and achieving food security. A key barrier to irrigation uptake is inadequate rural electricity supply for pumping and distributing water, besides other infrastructure deficits. Here we devise a spatially explicit integrated modelling framework to show that over one third of unmet crop water requirements of 19 major crops in smallholder cropland of SSA could be supplied with standalone solar photovoltaic (PV) irrigation systems that can be paid back by farmers within 20 years. This accounts for 60 km3 yr−1 of blue irrigation water requirements distributed over 55 million ha of currently rainfed harvested area (about 40% of the total). Crucially, we identify 10 million ha with a profit potential >$100 ha−1 yr−1. To finance such distributed small-scale infrastructure deployment and operation, we estimate an average discounted investment requirement of $3 billion yr−1, generating potential profits of over $5 billion yr−1 from increased yields to the smallholder farmers, as well as significant food security and energy access co-benefits. We demonstrate the critical importance of business models and investment incentives, crop prices, and PV & battery costs in shaping the economic feasibility and profitability of solar irrigation. Yet, we find that without strong land and water resources management infrastructure and governance, a widespread deployment of solar pumps may drive an unsustainable exploitation of water sources and reduce environmental flows. Our analysis supports public and private stakeholders seeking to target investments along the water–energy–food–economy–sustainable development nexus.

Experimental Performance Evaluation of a PV-Powered Center-Pivot Irrigation System for a Three-Year Operation Period

High-power diesel-based or grid-connected irrigation systems are being replaced by battery-free, high-power stand-alone Photovoltaic Irrigation Systems (PVIS) that reduce energy costs by up to 80% and for which no experimental performance data are available. The operation of PVIS is affected by various factors, some unrelated to the quality of the PV system itself, that generate losses that affect their performance: losses that vary with the crop and its irrigation period, losses intrinsic to the PVIS design, and losses that happen as a consequence of the behavior of the end-user. To better understand the impact of each type of loss, the traditional performance ratio was factorized. This paper provides the PV community with experimental data on the performance of a battery-free 160 kWp PV-powered constant-pressure center-pivot irrigation system. The system was analyzed over three years of real operation, during which the performance ratio ranged from 49.0 to 53.2%.

Performance analysis of polycrystalline floating photovoltaic array: The concept and prototype development for irrigation purpose

AbstractThe concept and design of the 2 kWp polycrystalline floating photovoltaic (PV) system for agricultural irrigation purposes are presented in this paper. The well‐known major advantage of the floating PV system is its installation in the presence of water, which leads to cooling of the PV system that improves its efficiency. In addition to that, the floating PV system reduces the wastage of cultivation area required for its installation, and also, it reduces evaporation of water (for 20% of float cover) by the factor of 22.23 cm/year. But the floating PV systems face some confrontations such as low electrical reliability and reduced life of the mechanical structure due to nearby water surface. As an attempt to overcome the above issues, a small‐scale floating PV system prototype in a water reservoir at Kothavadi village, Tamil Nadu, India has been developed. The system comprises of a floater, mechanical structure, PV module, supporting anchor, under water cable, and motor. The power generated out of this proposed system is utilized for pumping the water from a nearby bore well, and pumped water is stored in the same reservoir where the floating PV system is installed. The water in the reservoir can be used by the farmer for their necessity. In this study, the energy production (month by month) is monitored. Furthermore, the economic analysis and PV modeling have been performed along with some maintenance aspects. The study helps the scientists and engineers to comprehend the performance and commercial viability of floating PV for rural farmers. It is anticipated that this work will inspire and direct farmers to install a floating PV irrigation system as a perfect alternate for the conventional systems.

A New Strategy for PI Tuning in Photovoltaic Irrigation Systems Based on Simulation of System Voltage Fluctuations Due to Passing Clouds

One of the greatest challenges in stand-alone photovoltaic irrigation systems (PVIS) without batteries is the tuning of PID controllers and the evaluation of their performance once the system is tuned. Tuning method must be applied in clear days (constant irradiance) while performance must be evaluated in the most unfavourable circumstances, which occur when the passage of a cloud causes a sudden drop in available power. In short, tuning and testing must be done under different weather conditions. To solve this problem, a tuning method that is complemented by a method to simulate voltage fluctuations due to cloud passage has been developed. This allows tuning and evaluation of the system’s performance in the same session. Furthermore, the new PI tuning method achieves a better adjustment of the parameters and solves the instability problems that arise when applying traditional closed-loop tuning methods. Both methods use the feedforward input that most variable frequency drivers have. A signal generator is used to carry out the simulation of the clouds. This input is also used to introduce a triangular signal used for the tuning of the PI controller. The results show that the performance of the system, characterized by the voltage of the PV generator, with simulated clouds is similar to the response with real clouds. With regard to the tuning, the new method achieves better performance than previous methods. These methods can be applied on clear days, under conditions of constant irradiance, which greatly simplifies its implementation and greatly reduces the time required for commissioning the system.

Modeling and Simulation of Multipumping Photovoltaic Irrigation Systems

The growing market of large-power photovoltaic irrigation systems (PVISs)—made of systems with different and several motor pumps working in parallel—needs simulation tools capable to estimate their energy and water productivity. The objective of this paper is to present the simulation models developed for parallel multipump PVISs fed by a single PV generator. These models seek to maximize the instantaneous water flow rate according to the available PV power and were developed for the typical configurations of large-power irrigation facilities. The models present some advantages when compared with the current state of the art (in which a single motor pump connected to a 1/N fraction of the PV generator is simulated and the result is multiplied by N): in the case of negligible hydraulic friction losses, the use of the multipump model shows gains with respect to the state of the art; in the case of appreciable friction losses, the current state of the art overestimates the productivity of the systems. Then, the ability of these models to compare different multipump designs is shown: two groups of pumps working at variable frequencies show better performance than a group working at a variable frequency and a group at a nominal frequency—an 8% increase in the water pumped is seen.

A Blockchain-Based Financial Instrument for the Decarbonization of Irrigated Agriculture

Farming and food production sustainability increasingly depends on the availability of a clean energy model for irrigated agriculture. This can be achieved by massively introducing photovoltaic irrigation systems (PVI) with sufficient quality and reliability. Nevertheless, such PVI projects require high upfront investment and long payback times, so access to long-term, low-cost capital is essential to ensure their competitiveness. In this regard, decentralized financial (DeFi) solutions based on blockchain (BC) technology present a number of features that can be applied to produce financial instruments (FI) well suited to attract investors to PVI projects and to reduce the cost of clean energy for irrigators. In order to assess such a possibility, a DeFi FI tailored for PVI has been produced and implemented in BC. We demonstrate that a single smart contract executed in a distributed ledger can execute the different tasks related to the securitization of PVI assets. The impact on the cost of capital for PVI projects is significant, leading to an estimated reduction in the cost of clean energy for irrigators of 22%. Nevertheless, decentralization also introduces a number of specific risks that must be considered and mitigated.

On the tuning and performance of Stand-Alone Large-Power PV irrigation systems

• A new systematic method of tuning the PID control of frequency converters. • First experimental values of performance for large-power PV irrigation systems. • The average number of abrupt stops per day decreases by more than 80%. • A passing-cloud resistance ratio value greater than 95% can be required. • The expected PR in good quality PV irrigation systems pumping to a water pool is 65%. Stand-alone large-power PV irrigation systems without batteries is a recent innovation. This means that their design has not yet reached maturity and there are no experimental data about their performance available. This paper is a contribution, on the one hand, to the systematic tuning of the control of this type of systems and, on the other hand, to the knowledge of their experimental performance data. A systematic Proportional, Integral and Derivative (PID) control tuning method for frequency converters is proposed, based on the application of the Approximate M−constrained Integral Gain Optimisation (AMIGO) design rules to the frequency response tuning method, and applied to two PV irrigation systems, located respectively in Villena and Aldeanueva de Ebro, Spain, that had a “conservative” tuning by means of an experimental trial and error method. To check the goodness of this systematic tuning, the experimental performance of both systems has been evaluated from 2017 to 2021. New indices have been proposed to assess both the robustness of the system to PV power fluctuations (the “Number of abrupt stops” and the “Passing-cloud resistance ratio”) and the performance (by factoring the traditional Performance Ratio ( PR ) to determine the influence of different factors external to the system). Results show that the percentage of abrupt stops improves from 40% and 39.8% in each PV irrigation system prior to systematic tuning to 7.3% and 1.3% after tuning; the passing cloud ratio increases from 65% and 79% to 97.9% and 99.8% and the PR from 61.4% and 60% to 65.7% and 64.7%.

Automatic irrigation monitoring system based on photovoltaic solar energy with fuzzy logic

Indonesia’s food self-sufficiency program requires the use of paddy fields with rice as the main food. That irrigation infrastructure problem also needs efficiency mitigation of cost impact using fuel oil in operation manually of engine irrigation. An automatic photovoltaic irrigation system can solve the problem of deficiency irrigation infrastructure, especially in the dry season as a more efficient power supply for irrigation infrastructure. In this research, implemented the automatic photovoltaic irrigation system is combined with the sunlight tracking system to get power supply, according to the direction of the sun. The irrigation pattern requires the suitability of soil moisture, water level, and power supply voltage as variables for the application of an automatic photovoltaic irrigation system. An automatic photovoltaic irrigation system is equipped with a website to monitor the irrigation variables. The Irrigation variables data is obtained from sensor readings then sent by NodeMCU to the website and calculates the suitability of irrigation variables as parameters using fuzzy logic to control automatic irrigation. The conclusion from this study was obtained after testing the system with the system running well, fuzzy logic parameters run with variables value of voltage > 9.9 Volt, water level < 2cm, and soil moisture < 69%.

Optimal Design of Photovoltaic Irrigation System with Different Nozzle Numbers

HighlightsWhen the photovoltaic irrigation system is loaded with different numbers of nozzles, the working pressure of the nozzle will change. This is because the pipeline characteristics have changed with the variation of nozzle number. So the pump operating point changes and its head will also change, which leads to the change of working pressure of nozzle. To solve this problem, by theory analysis based on the test results, it is feasible to make the pump flow rate/head curve flatter. In this case, when the system pipeline characteristics change, the pump head changes little.This article presents a new optimization method to improve the performance of photovoltaic irrigation systems under variable load. The method just needs to optimize the four pump impeller structure parameters, which can make the pump flow rate/head curve flatter. So the pump head changes a little when the system is loaded with different numbers of nozzles, which can make the working pressure of the nozzle stable and improve the system performance.Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity.Abstract. The performance of the photovoltaic irrigation system under variable load were obtained and analyzed through test measurement. The adaptability of the system under variable load could be improved by optimizing the pump impeller structure, and then the irrigation uniformity of the photovoltaic irrigation system under different loads could be improved. Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme and the test verification was carried out. The range method was applied to analyze the simulation results. It can be found that when the geometric parameters of the impeller are D2 = 86 mm, ß2 = 41°, b2 = 4.0 mm, and Z = 9, the slope of the pump flow-head curve is the highest. The system performance after optimization was measured and compared with the original scheme. By comparison, it was drawn that when the system is loaded with different numbers of nozzles, the nozzle pressure can be maintained near the optimal pressure of the nozzle within a wider light intensity. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity. Keywords: Nozzle, Orthogonal test, Optimal design, Photovoltaic irrigation, Pump.

Designing an irrigation system using photovoltaic energy by considering crop type in Fergana Valley

Today, the importance of energy cost and efficiency is gradually increase. The decrease in drinking water and agricultural water resources, increases the interest in drip irrigation systems in agricultural irrigation. Environmentally friendly photovoltaic drip irrigation systems (PVDIS) are the appropriate solution in regions where there is no electricity distribution network, where it is far away, or where power cuts are frequently. This study is carried out in the Fergana Valley of Uzbekistan. Regional climate data obtained from Climwat 2.0 software are processed in Cropwat 8.0 software. Crops that are both the source of livelihood of the people of the region and that can be used in this study have been determined. Annual and daily water needs are analyzed so that these crops are irrigated every seven days. A system is designed by taking the data of the crop with the highest water requirement as a reference. The drip irrigation system is set up in a PVsyst 7.1.7 simulation environment to pump 114.24 m3 of water daily from a 5-meter-deep river with a 1.8 kW photovoltaic system. The efficiency of the system is 58.7% and the efficiency of the pump is 34.5%. Crop water need is met at the rate of 98.87%. It is predicted that the designed and analyzed PVDIS will provide efficiency in energy and water resources.

Multistage Bounded Evolutionary Algorithm to Optimize the Design of Sustainable Photovoltaic (PV) Pumping Irrigation Systems with Storage

Small off-grid photovoltaic (PV) pumping irrigation systems with storage tanks are an environmentally friendly, cost effective and efficient way of taking advantage of solar energy to irrigate crops, and they are increasingly being used today. However, finding the optimal design of this type of system is cumbersome since there are many possible designs. In this work, a new heuristic method based on the hybrid approach, which uses search space reduction, is developed and adapted to the optimal design for this type of PV irrigation system. At different stages, the proposed approach iteratively combines a bounding strategy based on the application of engineering rules with the aim of reducing the search space with a genetic algorithm to find the optimal design within this search space. The proposed methodology was applied to minimize the cost of a benchmark case study consisting of a real farm placed in the province of Almería (Spain). The proposed methodology was able to provide a faster and an accurate convergence due to the reduction of the search space. This fact led to a reduced total cost of the system. This study proved that the most sensitive variables were the number of modules and the type of pump, whereas the diameter of the pipe and volume of the storage tank remained more stable.

Optimal management of a multisector standalone direct pumping photovoltaic irrigation system

Standalone direct pumping PV irrigation systems are a special type of PV system in which water is not lifted to a tank but, instead, is pumped to the irrigation system to satisfy the crop water needs. The operation of these PV irrigation systems requires efficient new operation rules in order to maximize the energy use efficiency as the PV energy must be used instantaneously. In this work, we introduce a new multisector approach based on the simultaneous operation of several irrigation sectors according to the incoming energy. An innovative analytical model was implemented in order to optimize the operation of a multisector PV irrigation system. The proposed model was evaluated by applying it to a case study. The results of said study showed that simultaneous operation reduced the cost of the PV plant since it required a lower number of PV modules (lower Peak power) and it also outperformed the individual operation scenario in terms of energy use efficiency as 18.4% of the potential PV energy was effectively delivered to the irrigation sectors (only 15.4% for individual operation). The design of the irrigation system was also affected by the adopted operation strategy. Lower nominal flowrate of the emitters and higher irrigation time per sector were preferable in simultaneous operation than in the case of individual operation.

Comprehensive sizing methodology of smart photovoltaic irrigation systems

The use of photovoltaic (PV) energy in irrigation is increasing its relevance as energy source in irrigated agriculture. The main reason relays on its economic and environmental benefits, compared to traditional options. To reduce economic, materials and energy requirements of PV irrigation systems, its design and dimensioning should be optimal. In this work, we developed the model MOPISS (Model for Optimal Photovoltaic Irrigation System Sizing) focussed on the selection of pipe diameters and PV plant dimensioning, optimizing jointly the investment cost and operation of the system. MOPISS, developed in MATLAB™, integrated a customized version of the Non-dominated Sorting Genetic Algorithm (NSGA-II) with two objective functions, aimed at searching the optimal sizing of the irrigation network and PV plant. The results showed a series of solutions with optimal hydrants grouping in sectors, pipe diameters and PV plant size. MOPISS was applied to a real case study obtaining solutions which satisfied 96 % of the irrigation requirements while saved cost between 22.9 and 38.2 % over the total investment cost, compared with the original design. MOPISS is a useful tool to produce optimal designs of sizing new PV irrigation system under a comprehensive approach that considers crop, water and energy availability and network layout.

An assessment of the proportional-integral control tuning rules applied to Photovoltaic Irrigation Systems based on Standard Frequency Converters

In this work, a systematic study of different tuning rules of proportional-integral (PI) control parameters applied to Photovoltaic Irrigation Systems (PVIS) based on Standard Frequency Converters (SFCs) has been carried out. A laboratory system has been implemented to obtain the PI control parameters by means of the most widely accepted tuning rules in control systems. Based on the step-input response modeling, we have been applied the tuning rules of Ziegler-Nichols (ZNs), Chien-Hrones-Reswick (CHR), Cohen-Coon (C-C), Lambda and AMIGOs. Based on frequency response modeling we have been applied the tuning rules of Ziegler-Nichols (ZNf) and AMIGOf. The PI controller parameters obtained from these tuning rules have been evaluated by performing two types of tests: start-up and sudden drop of the available PV power. The experimental results show that the parameter sets obtained by the ZNs, CHR and AMIGOf rules are the only ones that pass all the start-up tests and that the tests of sudden drop of the available PV power are only passed by the configuration obtained by the AMIGOf rules. Therefore, it has experimentally verified that the AMIGO tuning rules based on the frequency response modeling are the only ones that provide adequate values for the PI control parameters for PV irrigation systems.

Comparative analysis of the economic feasibility of five large-power photovoltaic irrigation systems in the Mediterranean region

The electricity costs for agricultural applications is dramatically increasing in the last years, making the solutions based on photovoltaics more attractive once the technological barriers that impeded high-power PV irrigation systems (PVIS) have been removed. But the data available in the literature are restricted to small-power PVIS what limits the feasibility assessment of the investment in this kind of systems for agricultural applications. This paper presents a comparative economic feasibility analysis of five large-power PVIS in the range from 40 to 360 kWp in the Mediterranean region, considering the investment required for each installation and the savings that they produce based on the real data of their performance during the years 2016 and 2017. The results show that the investment in PVIS in the Mediterranean region is always profitable, for all of the PVIS configurations and the powers considered in this study and even with frequent occurrences of events of lack of water that obliges the PVIS to stop, showing IRR values between 10 and 28%, and LCOE values ranging from 0.04 to 0.20 €/kWh. Moreover, the results allow concluding that PVIS that has a seasonal water pool and a strong water source show the best results in the feasibility analysis and, therefore, in order to segment the market for the introduction of large-power PVIS, the substitution of conventional power in this kind of existing irrigation networks, would be the priority.

Middleware to Operate Smart Photovoltaic Irrigation Systems in Real Time

Climate change, water scarcity and higher energy requirements and electric tariff compromises the continuity of the irrigated agriculture. Precision agriculture (PA) or renewable energy sources which are based on communication and information technologies and a large amount of data are key to ensuring this economic activity and guaranteeing food security at the global level. Several works which are based on the use of PA and renewable energy sources have been developed in order to optimize different variables of irrigated agriculture such as irrigation scheduling. However, the large amount of technologies and sensors that these models need to be implemented are still far from being easily accessible and usable by farmers. In this way, a middleware called Real time Smart Solar Irrigation Manager (RESSIM) has been developed in this work and implemented in MATLABTM with the aim to provide to farmers a user-friendly tool for the daily making decision process of irrigation scheduling using a smart photovoltaic irrigation management module. RESSIM middleware was successfully tested in a real field during a full irrigation season of olive trees using a real smart photovoltaic irrigation system.